Fig. 2

Both bugeye^mw1 and bugeye^p5bnc mutants have non-sense mutations in lrp2.

A Genetic and corresponding physical map of the critical interval for bugeye^mw1 and bugeye^p5bnc locus on chromosome 9. Associated number of recombination events per 270 meioses are shown for each polymorphic marker. SSR, Simple sequence repeat. B Sequence comparisons of lrp2 revealed distinct non-sense mutations in bugeye^mw1 and bugeye^p5bnc. In mw1, the cysteine at amino acid position 23 is changed to a stop codon by a T>A mutation; in p5bnc, the glutamine at 413 is changed to a stop by a C>T mutation. In both, heterozygous genotypes show both alleles. C Model of Lrp2 protein structural domains, with the locations of the identified mutations indicated by arrows. The bulk of the protein is extracellular with ligand binding domains, while the intracellular domain contains an NPXY endocytosis sequence motif. D-E Immunostaining for Lrp2 in 56-hpf pigmentation-blocked embryos. Lrp2 immunoreactivity was robust in the retina pigmented epithelium (RPE) of wild-types (D), but absent in bugeye embryos (E). Insets in D and E are magnified in D′ and E′. Scale bars = 25 µm; circles show placement of the lenses. F Images of ethidium bromide stained agarose gels show restriction fragment length polymorphism (RFLP) genotypes: homozygous mutant (-/-), heterozygote (+/-) and wild-type (+/+) genotype for each mutation.